In the multi-viewpoint video encoding, at least one basic viewpoint and one dependent viewpoint are contained. The basic viewpoint is encoded independently, while the dependent viewpoint can be encoded with reference to the basic viewpoint. Different viewpoints are photographed by cameras from different angle of views, so there are disparities between viewpoints. In the multi-viewpoint plus depth video encoding, each viewpoint also comprises at least two layers, i.e., a texture layer and a depth layer.
In the AVS2-3D video coding standard, the disparity value between a dependent viewpoint and a basic viewpoint is expressed by a Global Disparity Vector (GDV) tool. Specifically, for each picture in each layer (the texture layer or the depth layer) in each dependent viewpoint, a two-dimensional GDV is transmitted in the picture header to identify the disparity of the current picture relative to a corresponding picture (having a same display order index) in a corresponding layer of the basic viewpoint. The GDV can be used to search a corresponding encoding block from the corresponding picture for the encoding block in the current picture, so that the inter-view redundancy is eliminated, and the compression efficiency is improved. In the AVS2-3D, the GDV regards a picture as a transmission unit, and each picture transmits a two-dimensional disparity vector integrally. However, this encoding method leads to a larger number of coding bits and a low coding efficiency.